1. Technical Field
The present invention relates to a resin for an electrostatic-image-developing toner and, an electrostatic-image-developing toner and, an electrostatic image developer, an image-forming method, and an image-forming apparatus.
2. Related Art
In recent years, in the toner for electrophotography, in addition to conventional requirements for higher image quality and higher productivity, further energy saving manufacture of toners has been required from the viewpoint of the reduction of environmental load.
For satisfying these requirements for the toner for electrophotography, the manufacturing method of the toner has been shifting from conventional methods of melting and kneading resins at a high temperature of 100° C. or more, and then grinding and classifying to the what is called chemical manufacturing method such as an emulsification polymerization flocculation method and a suspension polymerization method of manufacturing a toner at a temperature of 100° C. or less and, further, capable of more precisely controlling powder characteristics of the toner such as the grain size and structure of the toner as compared with the kneading and grinding methods.
In these toners by chemical manufacturing methods, a vinyl polymer that is a polymer from a radically polymerizable vinyl monomer has been used as the resin component. However, in the requirement for further higher image quality and a low energy electrophotographic system in the market, conversion of toner resin components from conventional vinyl polymers to various kinds of polycondensation resins including polyester resins, and use of blended resins of these polycondensation resins with vinyl polymers have been examined.
In this case, in the conversion to polycondensation resins in the toners by chemical manufacturing methods, there remain great problems in the manufacturing methods. In the manufacture of the toners by chemical manufacturing methods, processes of dispersion and emulsification of toner resins in an aqueous medium are essential. In the use of radically polymerizable vinyl polymers in the present situation, dispersion of resin grains in an aqueous medium can be industrially easily manufactured by emulsion polymerization and suspension polymerization methods. Contrary to this, in the case of polycondensation resins such as polyester, it is difficult to use these techniques as principle. Therefore, after resins are once polymerized by block polymerization or solution polymerization, the resins are processed by a high shearing mechanical dispersing method that necessitates a great amount of dispersants and a vast quantity of energy, and a phase inversion emulsifying method of phase inverting the resins with an organic solvent, and then finally removing the organic solvent.
These methods have of course given rise to large problems from the viewpoints of the characteristics of the toner in the manufacture and environmental load.